列出数学成绩的排名(要求显示字段:学号,姓名,成绩,排名) declare @temp table(pm int identity(1,1),stuid int,name varchar(50),score int)insert into @temp select stuid,name,score from stuscore where subject='数学' order by score descselect * from @temp sql 聚合函数和group by 联合使用 列出数...
定义一个游标。DECLARE name [ BINARY ] [ INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR query [ FOR { READ ONLY | UPDATE [ OF column [, ...] ] } ]DELETE删除一个表中的行。DELETE FROM [ ONLY ] table [ WHERE condition ]...
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE table_name [ (column_name [, ...] ) ] [ [ WITH | WITHOUT ] OIDS ] AS query CREATE TABLESPACE 定义一个新的表空间。 CREATE TABLESPACE tablespace_name [ OWNER username ] LOCATION 'directory' CREATE TRIGGER 定义一个新的触发器。
PostgreSQL8.0.0 1.创建新表CREATE TABLE weather ( city varchar(80), temp_lo int, -- 最低气温 temp_hi int, -- 最高气温 prcp real, -- 降 POSTGRESQL 创建表 ci 字段 PostgreSQL 转载 mob64ca140ac564 1月前 17阅读 postgresql本地变量postman变量本地 ...
DECLARE TEMPORARY TABLE statement is not supported by PostgreSQL and by this extension. However this statement defines a temporary table for the current connection / session, it creates tables that do not reside in the system catalogs and are not persistent. It cannot be shared with other sessions...
tablepartitionsadd_month,按月生成分区表,一月一个分区表 CREATEORREPLACEFUNCTIONpublic.tablepartitionsadd_month( p_tablenametext, p_schematext, p_date_starttext, p_stepinteger)RETURNSvoid LANGUAGE'plpgsql'COST100VOLATILE PARALLEL UNSAFEAS$BODY$declarev_cntint; ...
DO $$DECLARE_idinteger:=2; _namevarchar(10) :='ZhangSan';BEGIN_id :=20;DROPTABLEIFEXISTStemptb;CREATETEMPTABLEtemptbASSELECT_idasid, _nameasname;END; $$;select*fromtemptb; 也可以手动创建临时表 ---创建临时表CREATETEMPORARYTABLEtemptb ( ...
PostgreSQL 命令-CREATE TABLE 定义一个新表。 CREATE[[GLOBAL|LOCAL]{TEMPORARY|TEMP}]TABLEtable_name({column_name data_type[DEFAULTdefault_expr][column_constraint[...]]|table_constraint|LIKEparent_table[{INCLUDING|EXCLUDING}DEFAULTS]}[,...])[INHERITS(parent_table[,...])][WITHOIDS|WITHOUTOIDS][...
postgres=# \helpSELECTCommand:SELECTDescription:retrieve rows from a table or viewSyntax:[WITH[RECURSIVE]with_query[,...]]SELECT[ALL|DISTINCT[ON(expression[,...])]][*|expression[[AS]output_name][,...]][FROMfrom_item[,...]][WHEREcondition][GROUPBYgrouping_element[,...]][HAVINGcondition...
DECLARE myvar INT; BEGIN SELECT COUNT(*) INTO myvar FROM users; END $$; 对比:MySQL直接设置变量,而PostgreSQL需要在块中声明和赋值。 38. 使用TEMPORARY表 MySQL CREATE TEMPORARY TABLE temp_users AS SELECT * FROM users; PostgreSQL CREATE TEMP TABLE temp_users AS SELECT * FROM users; ...